Numerous U.S. Patents are directed to controlling various laser parameters such as output energy, output pulse length, output pulse repetition rate, output pulse shape, output modes and mode locking. To effect such controls, apparatus is disclosed in these Patents which is directed to a) feedback loops which include the Q-switch (e.g., U.S. Pat. Nos. 3,774,120; 4,197,513; 4,959,838); b) Q-switch control with non-feedback means (e.g., U.S. Pat. Nos. 4,375,684; 4,675,872; 4,930,901); c) controlling laser cavity dimensions (e.g., U.S. Pat. Nos. 4,025,875; 4,964,132); d) the use of control means external to the laser (e.g., U.S. Pat. Nos. 3,747,019; 4,730,105; 4,483,005); e) shaping the Q-switch driving pulse (e.g., U.S. Pat. No. 4,752,931); f) switching or controlling the laser gain (e.g., U.S. Pat. Nos. 3,914,709; 4,319,203; 4,539,685; 4,768,198); and g) cavity dumping (e.g., U.S. Pat. No. 4,477,905). A U.S. patent related to laser application is U.S. Pat. No. 4,899,345 while stabilization of light intensity via feedback around an optical amplifier is addressed in U.S. Pat. No. 4,958,354.